Airfield runway light fixture extension



Feb. 13, 1968 B. c. CARTER 3,369,114

AIRFIELD RUNWAY LIGHT FIXTURE EXTENSION Filed Oct. 25, 1966 UnitedStates Patent 3,369,114 AIRFIELD RUNWAY LIGHT FIXTURE EXTENSION Ben C.Carter, Rte. 3, Box 130, New Bern, N.C. 28560 Filed Oct. 25, 1966, Ser.No. 589,446 12 Claims. (Cl. 240-12) This invention relates toflush-mounted airfield runway light fixtures, sometimes referred to asinset light units of the type having a receptacle or base part and acover or light-carrying part. More particularly, this invention relatesto extensions for use with existing light fixtures to provide a raisedmounting for the cover or light-carrying part of the fixture, theextension, being in electrical contact with the existing receptacle orbase member, in order to elevate the cover to a raised runway surfacesuch as when the runway is repaved.

Use of flush-mounted airfield runway lights recently has become common.These light receptacles are mounted in a shallow hole in runways,taxiways, aprons and the like made of concrete or other material, so asto be substantially flush with the top surface of the runway. Runwaysrequire constant maintenance and are regularly resurfaced, theresurfacing resulting in the raising of the runway surface. It, thus,becomes necessary to alter the existing light installations so that thelight is again flush with the paving.

It is an object of this invention to provide for remounting the cover orlight-carrying part of the fixture flush by utilizing the existingreceptacle and the existing elec trical circuitry, thereby to avoiddisturbing the pavement and existing wiring that is embedded in epoxy orother similar hard materials.

An other object of this invention is to provide an extension adapted tobe mounted directly upon the base part of an existing conventionalflush-mounted airfield runway light fixture and which is also adapted toreceive on the upper surface thereof the existing cover orlight-carrying part of the fixture.

Still another object of this invention is to provide an extension asaforesaid which also provides for electrical continuity between theterminals of the existing receptacle part and connections to the coverpart.

Other objects and advantages of the invention will become apparent asthe invention is described in connection with the accompanying drawing.

According to this invention, an extension is provided for raising theheight of an existing conventional airfield runway light consisting of areceptacle or base part and a cover or light-carrying part, saidextension including a duplicate of the base part and an electricallynonconductive body part, the lower surface of which is configured to bethe mating image of the upper surface of the existing base part so as topermit mated mounting thereon of the extension whilst the upper surfaceof the body part is configured to be mating image of the lower surfaceof the duplicate base part, whereby the original cover can be mounted onthe extension flush with the raised runway surface. A pair of insulatedapertures is provided through the extension aligned with existingelectrical contacts in the existing receptacle to provide passage formeans such as metal screws for electrically joining the cover and theoriginal receptacle.

In the drawing:

FIG. 1 is an exploded perspective view of a runway lighting unitacording to this invention, showing the cover and receptacle parts withthe new extension inbetween them. FIG. 2 is a perspective view of thebottom side of the extension of FIG. 1. FIG. 3 is a fragmentarysectional ice view of the extension of FIG. 1, the section being alongline 3-3 of FIG. 1, mounted on the receptacle part.

Referring to the drawing, a known type of runway centerline lightfixture is illustrate-d in FIG. 1 together with the new extension. Theknown fixture comprises a circular metallic base member, designatedgenerally by numeral 10, in the form of a flanged disc having acontinuous bottom wall 12 and a circular peripheral wall 14, the upperedge of which is offset outwardly forming a shoulder 16 and thenupwardly forming rim 18r and downwardly forming skirt 18s. Atdiametrically opposite positions spaced inwardly from the peripheralwall, two bosses 15, 15' are formed integrally with the base member andrise from the bottom wall 12. These bosses are bored and tapped for thereception of securing screws (not shown).

Also at oppositely, but non-symmetrically spaced positions rising fromthe bottom wall adjacent the peripheral wall are two more bosses 17, 17'which are bored and tapped to receive terminal screws (not shown). Webs13 extending from one boss to another and to the peripheral Wall 14 maybe provided to strengthen the structure. The terminal screws passthrough the bosses 17, 17' and thread into small fiat terminal plates ornuts 19: (FIG. 3) to which pigtail wire leads 19w are soldered, thewires being led around in an internal groove or channel in the bottomface of the base member to an aperture 18a in the skirt 18s. Theterminal plate 19t is insulated from the base member 10 by an insulationplate 10p, and the terminal screw is insulated from the base member by aflanged insulating sleeve 10a.

In the known type of runway lighting unit, a cover member designatedgenerally by numeral 20 is circular and of generally disc-shape and ofsuch dimension that it will fit within the lip 18 and lie on theshoulder 16 of the base member 10. The cover is formed with one or moreradial channels 22 depressed into its top surface, flaring outwardlyfrom a lens 24 mounted in the depression near the center of the cover.

The cover has mounted on its inner or under surface a known type ofelectric lamp and terminals for wire connections (not visible) to theterminal screws that pass through the bosses 17, 17 of the base. Sincethese details are not, per se, part of this invention, furtherdescription and illustration of them are not given, but reference may bemade to Patent 3,113,726 for a suitable example.

The cover-was originally secured to the base by screw bolts passingthrough holes 26 in the cover and threading into the tapped bores in thebosses 15, 15 of the base 10.

When a device having the parts above described is originally installed,the cover 20 is flush with the runway surface.

When the runway is resurfaced, the base portion 10 advantageouslyremains in place, so that repositioning will be avoided and movement ofthe incoming and outgoing wiring ducts and wire connections will beunnecessary. However, due to the runway surface having been raised bythe new pavement, the cover must be raised to the new pavement level. 1

For that purpose, the present invention provides an extension which isdesigned and constructed to be placed between the existing base andcover members. The extension is advantageously and economicallyconstructed by taking a duplicate 30 of the base member 10 and moldingonto the bottom a solid body 32 whose lower surface is configured tomate exactly with the upwardly facing surface of base 10 in all itsconfigurations, as if the hollow upper portion of the base were itselfused as the bottom half of a mold.

The material of which the body 32 is made is preferably a mixture of asynthetic plastic cement and blasting sand.

This mixture is advantageous because it is non-corrosive and is a goodelectrical insulator. However, the invention is not restricted to thismixture as other mixtures, or metal, may be used. But, if metal is used,then insulating sleeves should be used wherever contact screws passthrough the extension.

When the body is molded or cast onto the duplicate base 30 and hardens,the body part 32 and the duplicate base portion 30 permanently mergetogether inseparably to form a single integral unit. This is thepreferable construction. However, the body part can be made separate andcaused to adhere together by an adhesive or can be secured together bybolts or other common securing means.

It is possible to put two base portions together and use them as the topand bottom of a mold, with the space between them filled with themixture, provided of course the top surface of the bottom of thethus-formed mold can be, or is coated so that it can be parted from theresulting molded body. This procedure is only possible when the heightof the extension is to equal or exceed the height of two stacked basemembers 10.

As a result of the molding, mating recesses 31, 33 are provided for thewebs and bosses of the base member The height of the extension may vary,but in all cases in which the cover is to be raised more than the heightof the outside peripheral surface of the base member, the peripheralwall of the body will be of the same dimensions and form as theperipheral walls of the base members 10 and 30 so that there is acontinuous peripheral side Wall of the assembly when the parts areassembled.

While it is preferable for the bottom surface of the body 32 to be amating counterpart of the upper surface of the member 10, completecounter-identity is not an absolute essential. Substantialcounter-identity will sufiice. In other words, there may be some voidswithin the body 32 which are larger than, or are not required by,upstanding protuberances on the base 10. Rim and central support aredesirable, and also a continuous exterior wall to keep out dirt andmoisture.

When the cover and base 10 were originally installed, terminal screwspassed through axial holes in the bosses 17, 17 and threaded into theterminal plates 191 which, as illustrated, are located in recesses inthe bottom face of the base 10. The recesses are filled and the terminalplate is covered by wax or other insulating material, as is common incovering exposed parts.

When the extension is put in place, the aforesaid terminal screws areremoved and longer terminal screw bolts 36 are substituted as in FIG. 3,passing through aligned screw-bolt passageways 38 in the duplicate baseportion 30 and body 32 of the extension. Wire or other connections tothe electric light bulb (not visible) in the cover 20 will be made tothe substituted terminal screws.

When the body 32 is made of the insulating material as described, orother suitable insulating material, insulation such as tubular sleeves34 and flanged sleeve 35 is not necessary. But when the body 32 isconductive, such sleeves are needed. In all cases, the flanged sleeve10g is used.

In use, it is assumed that a conventional fixture consisting of base 10and cover 20 already exists, fiush mounted in an airfield runway. Inorder to raise the level of the cover 20 to the raised level of therunway after repaving thereof, the existing base 10 is lightlysandblasted to remove all dirt, varnish, etc., and is then coated withan adhesive material such as an epoxy cement. The extension is thenmounted on the existing base 10'. The extension can fit only in oneorientation on the base 10 because the bosses 15, 15 arenon-symmetrically placed.

After the extension is in place, two electrically conductive contactscrew-bolts 36 are inserted through the screw hole 34 in the extensionand electrically engage the terminal plates 191 in the existing basemember 10. Thus.- this invention provides a means for permitting use ofa conventional lighting fixture without disturbing an existing basemember and without requiring rewiring since electrical continuitythroughout the existing base and the raised and newly mounted cover isinsured.

The extension is a unit which is easily manufactured, for example bymolding as described, and it is easily mounted. Alignment of theextension with the existing base is insured because of the mating matchtherebetween.

Whilst in the specification and drawings a particular electric fixtureand a configuration of an extension for use with that fixture isillustrated, the principle of the invention is adaptable to otherfixtures having different configurations. Many modifications within thescope of the invention will occur to those skilled in the art.Therefore, the invention is not limited to the details and example shownand described.

What is claimed is:

1. For elevating the upper or flush surface of an existing flush-mountedlighting fixture of the type having base and cover members, an extensioncomprising a body having a lower surface configured as substantially themating image of the upper surface of the base member of an existinglighting fixture, said body having an upper surface configured assubstantially the mating image of the lower surface of the base memberof a second lighting fixture to be mounted thereon, said body includinga pair of apertures extending therethrough, at least one of each of saidapertures being aligned with an electrical wire terminal provided onsaid existing first lighting fixture, said lower and upper surfaces ofsaid body being spaced apart a distance equal to the desired elevationof the flush surface of said first existing fixture.

2. An extension as defined in claim 1 wherein said body is formed of anelectrically non-conductive and non-corrosive material.

3. An extension as defined in claim 1 including an electricallynon-conductive bushing mounted Within and traversing the length of atleast one of said apertures.

4. An extension as claimed in claim 1 which is comprised of said bodyand the base member of a lighting fixture which are in permanentadherence together, forming a single unit.

5. An extension as claimed in claim 1 which is comprised of the basemember of a lighting fixture onto the bottom surface of which said bodyis molded and permanently adhered, forming a single unit.

6. An extension as claimed in claim 5 in whichthe adhered base member isa duplicate of the base member on which the extension is to be mounted.

7. In combination, a first lighting fixture of the type having cover andbase members and having a pair of electrical wire terminals in the base,an extension comprising a body mounted on the base of said firstfixture, a second lighting fixture base member similar to the first andmounted on said extension body, said extension body having a lowersurface configured as substantially the mating image of the uppersurface of said first base member and said body having an upper surfaceconfigured as substantially the mating image of the lower surface ofsaid second base member, said lower and upper surfaces of said extensionbody being spaced apart a distance to elevate said second base member adesired distance above said first base member, said body including apair of apertures aligned with said electrical wire terminals, and meansextending from said second lighting fixture through each of saidapertures and electrically connecting with the wire terminal of saidfirst lighting fixture and providing electrical connecting means forwires connecting with said second lighting fixture, said connectingmeans also securing said first and second base members and saidextension body in assembled condition.

3. The combination as claimed in claim 7 wherein the connecting means isan electrically conductive screw bolt.

9. The combination as claimed in claim 7 in which the extension body ispermanently secured to said second fixture.

10. The combination as claimed in claim 7 in which said extension bodyis molded on and permanently adhered to the bottom surface of saidsecond base member forming a single unit.

11. The combination as defined in claim 7 Wherein said extension body isformed of an electrically nonconductive and non-corrosive material.

12. The combination as defined in claim 7 including an electricallynon-conductive bushing mounted within and traversing the length of eachof said apertures.

References Cited UNITED STATES PATENTS 3,015,717 1/1962 Angier 2401.2 53,257,552 6/1966 Converso 2401.2' 3,327,104 6/1967 Loch 2401.2

FOREIGN PATENTS 1,022,913 3/ 1966 Great Britain.

10 NORTON ANSHER, Primary Examiner.

W. A. SIVERTSON, Assistant Examiner.

1. FOR ELEVATING THE UPPER OR FLUSH SURFACE OF AN EXISTING FLUSH-MOUNTEDLIGHTING FIXTURE OF THE TYPE HAVING BASE AND COVER MEMBERS, AN EXTENSIONCOMPRISING A BODY HAVING A LOWER SURFACE CONFIGURED AS SUBSTANTIALLY THEMATING IMAGE OF THE UPPER SURFACE OF THE BASE MEMBER OF AN EXISTINGLIGHTING FIXTURE, SAID BODY HAVING AN UPPER SURFACE CONFIGURED ASSUBSTANTIALLY THE MATING IMAGE OF THE LOWER SURFACE OF THE BASE MEMBEROF A SECOND LIGHTING FIXTURE TO BE MOUNTED THEREON, SAID BODY INCLUDINGA PAIR OF APERTURES EXTENDING THERETHROUGH, AT LEAST ONE OF EACH OF SAIDAPERTURES BEING ALIGNED WITH AN ELECTRICAL WIRE TERMINAL PROVIDED ONSAID EXISTING FIRST LIGHTING FIXTURE, SAID LOWER AND UPPER SURFACES OFSAID BODY BEING SPACED APART A DISTANCE EQUAL TO THE DESIRED ELEVATIONOF THE FLUSH SURFACE OF SAID FIRST EXISTING FIXTURE.